The ultrasonic liquid level measurement technology has been widely applied to the measurement of the volume of liquid. The basic principle is as follows: ultrasonic waves are emitted to the liquid level, and the reflected acoustic waves are received; then, the total distance traveled by the acoustic waves can be obtained according to the difference in time and the velocity of sound, and the height of the liquid level can thus be obtained; and, the volume of liquid is calculated by the height and the cross-sectional area of a container. However, in practical applications, this approach has several limitations: first, since the volume of liquid is indirectly obtained by the height of the liquid level, the sectional shape of the container is required to be consistent; or otherwise, the difficulty in calculation will be increased, or even the calculation cannot be performed; and second, since the ultrasonic waves have extremely high directionality, the calmness of the liquid level and the installation direction and stability of an ultrasonic probe are highly required, and it is very difficult to accurately measure the volume of water when the water level is not calm or the ultrasonic probe is deformed or displaced.
In view of the above deficiencies, the present invention provides a measurement method and device with high applicability and high accuracy.